High voltage switch



March 19, .1957 B. scHMATJKo y HIGH VOLTAGE SWITCH Filed Jan. 26, 1954 y.- W Jim ijnited States Patent HIGH VOLTAGE SWITCH Boris Sclnrnatjlro, Kassel, Germany, assignor to Licentia Patent-"Verwaltungs-G. m. b. H., Hamburg, Germany Application January 26, 1954, Serial No. 406,273

Claims priority, application Germany January 29, 1953 7 Claims. (Cl. 20G-148) rhe present invention relates to a high voltage switch, and more particularly to an improved compressed gas driven high voltage switch.

rlhere are known in the prior art high voltage compressed gas driven switches which have hollow switch arm electrodes and which have arranged within the hollow portion of the electrodes a centrally located electrode called an arcing electrode. The switch arms are formed with nozzles at the contact ends thereof. These switches are actuated by means of a stream of compressed gas which, for example, is made to impinge on a portion of one or more of the switch arms and to cause axial movement of the switch arms away from one another, and an arc to be drawn. During the opening of the swtich, the compressed gas is forced into the nozzle and through the hollow portion of the arm at extremely high velocity. This causes the arc formed during the opening of the switch to travel along the interior wall of the switch arm away from the nozzle end thereof and the base of the arc when it reaches the proximity of the arcing electrode, to jump to the arcing electrode. Just before the arc is finally extinguished by the compressed gas, it extends from one arcing electrode to the other arcing electrode rather than between the Contact ends of the arms and this prevents thermal overload of the main switch arm. Also, the use of the arcing electrode prevents the arc from easily being reignited.

When extremely high load currents are carried by the switch arm, it is necessary to increase the size of the hollow portion of the arm so that a greater quantity of co-mpressed gas can pass through the arrn in a given period of time. When so enlarged, the arcing electrode is then spaced so far from the inner wall of the switch arm that the arc which is formed on a contact end of the switch arm is blown back along the inner wall of the electrode and never jumps to the arcing electrode.

it is an object of the present invention t-o avoid the above-mentioned difficulty, that is, to provide a structure which, regardless of the size of the hol-low portion of the switch arm, will guide the arc and allo-w it to terminate at the arcing electrode.

in accordance with the invention there is provided a hinh volta e com ressed Gas driven switch includin a e e g conductive tubular contact electrode and an arcing elecl trode arranged within the tubular contact electrode and spaced from the contact end thereof. The arcing electrode is conductively connected to the tubular electrode. A conductive guide means disposed intermediate the tubular Contact electrode and the arcing electrode guides the arc formed when the switch is opened from the inner wall of the tubular electrode to the arcing electrode.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specic embodiments when read in connection with the accom panying drawing, in which:

Fig. 1 is a cross-sectional View of the contact ends of a pair of pressure driven switch arm electrodes according to the invention; and

Fig. 2 is a cross-sectional view along line Il--II of Fig. l.

Fig. 3 is a cross-sectional view taken along line III- III of Fig. l; and

Fig. 4 is a similar cross-section along line lV-IV of rFig. l.

Referring now to the drawing, there is shown a pair of hollow switch arm electrodes, 1, 2 and a pair of arcing electrodes 3, 4 arranged within the hollow portion of the switch arm electrodes. The contact end portions of the switch arm electrodes are of restricted cross-section and form nozzles. Arranged about the arcing electrodes are guiding electrodes 5, o the end portions 9 and 12 of which are formed of a refractory metal such as tungsten or molybdenum. The arcing electrodes and guiding electrodes are supported by conductive ns 7, S.

In operation, when the switch arm electrodes l, 2 are caused to move apart, an arc is formed between the contact ends of the arms. ln a conventional switch arm of restricted cross-section which contains only an arcing electrode,the arc is blown back from the nozzle endof fthe 'switch arm down the inner wall of the switch arm and the arc quickly jumps to the arcing electrode and is yfinally extinguished. However, when extremely high loads are involved and it is necessary to increase the diameter of the hollow portion of the switch arm to permit more gas to iiow, if no guiding member is present, the arc formed when the switch is opened is blown back down the inner wall of the switch arm and beyond the base of the arcing electrode. The arc is iinally extinguished without ever having jumped to the arcing electrodes. This, of course, is disadvantageous.

With the present invention the arc formed upon the opening of the switch is guided from the inner walls of the switch arms to the guiding members, 5, 6 and thence to the arcing electrodes 3, 4. The guiding member is so shaped that it forms an air foil and the gas is forced through this member at supersonic velocity. ri`he fins 8 and 7 are so arranged that they form rigid supportsfor the arcing electrodes and the guiding electrodes and provide a conductive connection to these electrodes so that all elements are at the same potential. As can be seen, the ns are narrow and so offer little resistance to the flow of compressed gas and similarly the guiding member is so arranged that it oiers little resistance to the ow of gas.

The guiding electrode is shown in the drawing as being cylindrically shaped, however, it is to be understood that the invention is not limited to this configuration. For example, the electrode can comprise simply a ring or can have a star-shaped cross-sectional conguration or other types of irregular cross-sectional configuration. Furthermore, this guiding member can be formed merely by extending the tins 7, 8 until they form a guide arrangement intermediate the arcing electrode and the inner wall of the switch arm electrode.

lt will be understood that each ot' the elements described above, or tw-o or more together, may also find a useful application in other types of voltage switches differing from the types described above.

While the invention has been illustrated and described as embodied in a compressed gas driven high voltage switch, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit yof the present invention;

Without further analysis, the foregoing will so fully' reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

l. In a high voltage compressed gas driven switch, at least one switch arm unit, comprising, in combination, a conductive tubular contact electrode having a contact end; an arcing electrode within said tubular contact electrode spaced from the contact end thereof and conductively connected thereto; and a hollow electrode arranged also in said tubular contact electrode surrounding a portion of said arcing electrode, said hollow electrode having a front end portion thereof located intermediate said arcing electrode and the contact end of said contact elec-v trode, said hollow electrode being conductively connected to said tubular contact electrode and said arcing electrode for guiding the arc formed during the opening of said switch from the inner wall of said tubular electrode to said arcing electrode.

2. In a high voltage compressed gas driven switch, at least one switch arm unit, comprising, in combination, a conductive tubular contact electrode having a contact end; an arcing electrode within said tubular contact electrode spaced from the contact end thereof and conductively connected thereto; a hollow cylindrical electrode arranged also in said tubular contact electrode surrounding at least an end portion of said arcing electrode, said hollow cylindrical electrode having a front end portion thereof located intermediate said arcing electrode and the contact end of said tubular contact electrode; and at least one narrow n fastened to the inner wall of said tubular contact electrode and arranged parallel to the axis of said tubular contact electrode for supporting said cylindrical electrode while offering little resistance to the flow of compressed gas.

3. In a high voltage compressed gas driven switch, at least one switch arm unit, comprising, in combination, a conductive tubular contact electrode having a contact end; an arcing electrode within said tubular contact electrode spaced from the contact end thereof and conductively connected thereto; a hollow cylindrical electrode arranged also in said tubular contact electrode surrounding at least an end portion of said arcing electrode, said hollow cylindrical electrode having a front end portion thereof located intermediate said arcing electrode and the Contact end of said tubular contact electrode, the end portion of said cylindrical electrode closest said contact end being formed of a refractory metal; and at least one narrow fin fastened to the inner wall of said tubular contact electrode and arranged parallel to the axis of said tubular contact electrode for supporting said cylindrical electrode while offering little resistance to the flow of compressed gas.

4. ln a high voltage compressed gas driven switch, at least one switch arm unit, comprising, in combination a conductive tubular contact electrode having a contact end; an arcing electrode within said tubular contact electrode spaced from the contact end thereof and conductively connected thereto; a hollow cylindrical electrode arranged also in said tubular contact electrode surrounding at least an end portion of said arcing electrode, said hollow cylindrical electrode having a front end portion thereof located intermediate said arcing electrode and the contact end of said tubular contact electrode, the end portion of said cylindrical electrode closest said contact end being formed of tungsten; and at least one narrow fin fastened to the inner wall of said tubular contact electrode and arranged parallel to the axis of said tubular contactvelectrode for supporting said cylindrical electrode while offering little resistance to the ow of compressed gas.

5. ln a high voltage compressed gas driven switch, at least one switch arm unit, comprising, in combination, a conductive tubular contact electrode having a Contact end; arcing electrode within said tubular Contact electrode spaced from the Contact end thereof and con ductively connected thereto; a hollow cylindrical electrode arranged also in said tubular contact electrode surrounding at least an end portion of said arcing electrode, said hollow cylindrical electrode having a front end portion thereof located intermediate said arcing electrode and the contact end of said tubular contact electrode, the end portion of said cylindrical electrode closest said contact end being formed of molybdenum; and at least one narrow n fastened to the inner wall of said tubular contact electrode and arranged parallel to the axis of said tubular contact electrode for supporting said cylindrical electrode while offering little resistance to the flow of compressed gas.

6. In a high voltage, compressed gas driven switch, the combination, comprising, a conductive, hollow, elongated switch arm having an axis along the long dimension thereof and formed with an orice in an end thereof, said arm being movable in axial direction from a first position in which said end thereof makes contact with another conductive member to a second position in which said end is spaced from said other member, there being an arc formed during the movement of said arm from said first position to said second position, said arm providing a passage for compressed gas which, during the movement of said arm to said second position, flows into said orifice and through the hollow in said arm so as to extinguish said arc; an arcing electrode conductively connected to said arm and located within the hollow portion thereof close to said orifice; a hollow cylindrical electrode arranged also in the hollow portion of said arm and surrounding at least a portion of said arcing electrode, said hollow cylindrical electrode having a front end portion thereof located intermediate said arcing elec trode and the contact end of said arm; and a plurality of fins fastened to the inner wall of said arm and arranged. parallel to the axis of said arm for supporting said arcing electrode and said hollow cylindrical electrode while offering little resistance to the flow of compressed gas.

7. In a high voltage, compressed gas driven switchfdie combination, comprising, a pair of aligned conductive, hollow, elongated cylindrical switch arms, each being formed with an orifice in an end thereof, said arms being` movable in axial direction from a first position in which the ends thereof formed with said orifice malte contact to a second position in which said ends are spaced from each other, there being an are formed during the movement of said arms from their first position to their second position, said arms, each providing a passage for compressed gas which, during the movement of said arms to said second position, flows into said orifices and through the hollow portions of said arms so as to extinguish said arc; a pair of arcing electrodes respectively connected to said arms and located within the hollow portions thereof close to said orices; and a pair of hollow cylindrical electrode means respectively arranged in the hollow portions of said arms surrounding the end portions of said arcing electrodes, each of said pair of hollow cylindrical electrodes being respectively located intermediate one of said arcing electrodes and the oriface of its respective arm, said orifices for guiding said arc from the inner walls of said arms to said arcing electrodes.

(References on following page) 5 l References Cited inthe lc of this patent UNITED STATES PATENTS Clerc July 24, 1934 Janssen Dec. 12, 1944 Amcr ct al. Dec. 12, 1944 Wilcox May 4, 1948 

